Letterboxd - Letterboxd is a social site for sharing your taste in film, now in public beta.
TMDB - free movie database
Similarkind - Helps you discover similar alternatives and recommendations for movies, tv shows, artists, bands, books and games.
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.
Taste - Get movie suggestions based on personal taste.
MovieLens - MovieLens helps you find non-commercial, personalized movie recommendations.